Not bad, although you'll eat up a lot of resources with the intermediary buffers, even with the slot limiters. I would say the only two buffers you need are the input iron/copper, the intermediary belts/inserters, and the resultant green packs (I like to do a parallel split buffer to queue up to 1,000 packs)

With only four science machines, it may be feasible to throttle the inserter production by only having one circuit setup. Greens are, what, 6 and inserters are .5. Even if you halve output of the inserters, you can still support 6 green pack factories. given you're only using four, you should have a fairly soft overproduction that will naturally throttle the belt factories.

however, with your setup, that means intermediaries will back up through the chests, eat up tons of resources that aren't going to things like your personal construction chests. Your factory will devour resources that should be going to 'personal' factories making gears, pipe, belts/fast/express belts, basic inserters, and circuits. Automating your construction materials is more important, imo, than having overdone material buffers for science packs. The last thing you want to be doing is building your own ciruits for solar panels >.<